The
catchment area of the Ganga lies between east longitudes 73°30’ to 89°
0’ and north latitudes 22° 30’ to 31° 30’ which falls in four
countries, namely India, Nepal, Tibet (China), and Bangladesh with major
part in India.

The Ganga basin extends over an area of 1,086,000 Sq km. The
drainage area lying in India is 862,769 Sq km which is nearly26.2% of the
total geographical area of the country. Out of the total basin area about
18,406.65 Sq km which
is only 1.695 % of the basin area falls in the Chhattisgarh state.